Toothbrushes of varying shapes and sizes are known in the prior art. A typical prior art toothbrush includes a rectangular or oval head, a handle, and a neck connecting the handle to the head. The head includes an array of bristles that are intended to remove plague and foreign matter from the teeth during use of the toothbrush. The head, neck, and handle are typically formed as an integral unit through a molding process. Typically, the central longitudinal axes of the head, neck, and handle are collinear or at least lie substantially in a common plane. In other prior art toothbrushes, the central longitudinal axis of the head may be oriented perpendicular to the central longitudinal axes of the neck and handle to form a toothbrush generally in the shape of a "T." The handle is often straight, but in some designs, is bent at certain locations and at certain angles either to make it more comfortable to hold and/or to improve the toothbrush user's ability to access hard-to-reach surfaces of the teeth.
As is known to those skilled in the art, toothbrushes clean most effectively when the toothbrush user uses the toothbrush such that the bristles are oriented substantially perpendicular to the tooth surfaces being cleaned. However, typical prior art toothbrushes can be difficult for certain individuals to use correctly and with relative ease. Such individuals who have difficulty using prior art toothbrushes include those persons who may not have full normal use of their hands and/or fingers, and/or who have impaired or underdeveloped hand or finger motor skills. Examples of such individuals include young children, arthritics, individuals with cerebral palsy, Parkinson's disease, or Alzheimer's disease, individuals with hand or finger malformities, the elderly, and persons debilitated through accident, illness and/or congenital abnormalities. For such persons, grasping a typical prior art toothbrush and properly manipulating it in the mouth during use such that the bristles engage the tooth surfaces to be cleaned substantially perpendicularly can be a difficult, if not nearly impossible, task. As a consequence, these persons oftentimes cannot, by themselves, brush their teeth in a manner sufficiently effective to maintain proper dental hygiene and oral health.
A variety of toothbrushes have been designed with the goal of aiding individuals with limited manipulative dexterity, especially children. Examples of such toothbrushes are disclosed in a variety of U.S. utility and design patents, such as U.S. Utility Pat. Nos. 1,257,883; 2,273,207; 3,214,776; 4,654,921; and 5,623,739, and U.S. Design Pat. Nos. 321,092; 324,958; and 389,312. Some of these toothbrushes typically include a closed oval or circular handle to facilitate easier gripping of the toothbrush and/or to insure that the toothbrush cannot be inserted dangerously deeply into the mouth or throat. In addition, U.S. Design Pat. No. 321,092 discloses a toothbrush having a tubular head with a circular cross-section and which bears bristles that extend outwardly from the head around the entire 360 degree perimeter of the head to virtually insure that at least some of the bristles contact the teeth irrespective of the angular orientation of the toothbrush head in the mouth.
Although prior art toothbrushes of the types described above do provide some maneuverability and gripping assistance to users, they still possess significant drawbacks. First, the closed oval or circular shape of the handles of such toothbrushes can limit a user's ability to maneuver the toothbrush in or toward the mouth area. For example, the closed loop shape of the handles of some of these brushes can impede the flex and extension movements of a user's (especially a young child's) wrist, thereby inhibiting the user's ability to properly orient the brush head in the mouth. Second, the closed loop shape of some of these brushes can also inhibit the ability of a caregiver to provide assistance or direction to an impaired user (e.g., a user with limited finger manipulative dexterity) while the user attempts to brush his or her own teeth. The closed loop handles typically do not provide enough space in the loop for both the user's fingers and two or more of a caregiver's fingers. Thus, a caregiver may not be able to provide assistance easily to an impaired user of a closed loop handle toothbrush who is in need of such assistance to brush his or her teeth. Lastly, closed loop handles do not guide the user (e.g., young child) to grasp or grip any particular part of the handle. Consequently, as the young child matures and gravitates toward using the more common straight-handled toothbrush, the child may still not be comfortable or adequate using such a straight-handled toothbrush, even though the child has been using a toothbrush with a closed loop handle, because the closed loop handle provides no direction as to the preferred location for gripping a toothbrush.
In addition to the aforementioned drawbacks related to the closed loop shape of some handles, many toothbrushes with closed loop handles include bristles that project outwardly from the head in a single general direction that is usually substantially perpendicular to a flat front surface of the head. Thus, even though an impaired user might be able to hold the oval or circularly-shaped toothbrush handle, he or she may not be able to properly orient and maneuver the tips of the bristles of the toothbrush head with respect to the tooth surfaces to be cleaned
U.S. Pat. No. Des. 321,092 appears to overcome some of the orientation problem by providing a toothbrush having bristles completely around a tubular head. When such a brush is used, however, at least one-half of its bristles will, at any given time, be oriented away from the tooth surfaces to be cleaned and, thus, do not contribute to effective cleaning action. Moreover, because its bristles project radially outwardly from the entire head, sensitive areas of the mouth that are not intended to be brushed, such as the cheek, will inevitably be brushed, possibly resulting in physical damage, irritation, or at least an uncomfortable sensation in such areas during brushing. Such irritation or discomfort in and of itself may discourage regular use of such a toothbrush.
Some straight-handled toothbrushes include bristles that project outwardly over a small range of directions that occupy, when the bristles and toothbrush head are viewed in cross-section, at most about a sixty (60) degree sector of a circular area containing the bristles and head. Examples of such toothbrushes can be found in U.S. Pat. Nos. 5,341,537 and 5,392,483. These toothbrushes include bristles along the longitudinal edges of the head that are flared slightly outward to clean and massage the gums and/or gumline under the presumption that the toothbrush head itself will be properly oriented in the mouth during use. However, as described above, such a presumption may not be correct, particularly when users have limited manipulative dexterity. Consequently, the gum and gumline cleaning of such toothbrushes may never be realized by some users.
Therefore, a need exists for a toothbrush and method of fabrication thereof that not only facilitate effective brushing of the teeth by individuals with limited manipulative dexterity, but that also improve maneuverability of the toothbrush and reduce the likelihood of irritating sensitive areas of the mouth during brushing. Such a toothbrush that also is amenable to caregiver assistance, provides overinsertion protection, and encourages the user to grip the correct part of the toothbrush handle would be a further improvement over the prior art.